Dispersion by pressure-driven flow in serpentine microfluidic channels
Dispersion by pressure-driven flow in serpentine microfluidic channels
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DOI：
10.1021/ie020149e
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发表时间：
2002-09-04
影响因子：
4.2
通讯作者：
Kim, S
中科院分区：
文献类型：
--
作者：
Rush, BM;Dorfman, KD;Kim, S
微流体流体动力学色谱在芯片上蚀刻的蛇形微通道中进行分析，在限制的情况下，芯片包含大量的周期性排列的转弯。在其他条件相同的情况下，将这些结果与与具有与曲线槽相同长度的直线槽的结果进行了比较。空间周期性系统的显式广义泰勒-阿里斯分散（宏观输运）理论适用于计算有效点尺寸的、物理化学惰性的布朗粒子夹带在低雷诺数、压力驱动的溶剂流中的芯片级溶质速度（U）和分散度（D）。注意力集中在相对较薄的渠道均匀的横截面，使各种运输领域有关的问题被表示为定期扰动膨胀相对于一个小的无量纲参数E，表示的比率通道半宽度曲线通道长度每转。对于任何足够“薄”的通道，对（U）在杆 * 和（D）在杆 * 上获得的一般领先阶数结果都是有效的，当考虑通道的“弯曲度”，即曲线蛇形长度与直线直通道长度之比的平方时，正式证明蛇形几何结构的结果简单地再现了直通道的结果--这一结论与直觉雅阁。
Microfluidic hydrodynamic chromatography performed in serpentine microchannels etched on chips is analyzed in the limiting case of chips containing a large number of periodically arrayed turns. Comparison is made between these results and those for a straight channel of the same length as the curvilinear channel, all other things being equal. Explicitly, generalized Taylor-Aris dispersion (macrotransport) theory for spatially periodic systems is adapted to compute the chip-scale solute velocity (U) over bar* and dispersivity (D) over bar* for effectively point-size, physicochemically inert Brownian particles entrained in a low Reynolds number, pressure-driven solvent flow occurring within the curvilinear interstices of such serpentine devices. Attention is focused upon relatively thin channels of uniform cross section, enabling the various transport fields pertinent to the problem to be expressed as regular perturbation expansions with respect to a small dimensionless parameter E, representing the ratio of channel half-width to curvilinear channel length per turn. The generic leading-order results obtained for (U) over bar* and (D) over bar*, valid for any sufficiently "thin" channel, formally demonstrate that the serpentine geometry results simply reproduce those for a straight channel, when account is taken of the channel's "tortuosity," namely the square of the ratio of curvilinear serpentine length to rectilinear straight channel length-a conclusion shown to accord with intuition.